It is common practice to use plastic screw anchors to mount devices such as drapery rods on a wall support surface. In general, the plastic screw anchors are formed with an axially elongated body adapted to be inserted into a hole drilled into a wall and the screw anchors have a screw receiving passage extending inwardly from one end. The plastic screw anchors are constructed and arranged so that a screw threaded to the screw receiving passage expands the anchor into firm engagement with the wall around the hole. Such screw anchors sometimes tend to turn in the hole during screwing of the screw into the anchor, particularly if the hole in the wall is a little oversized for the anchor or if the wall is formed of a soft material. Further, some devices have mounting pads with two or more fastener receiving openings to provide additional support for the device and to inhibit turning of the mounting pad on the wall, and some problems are presented in properly locating multiple screw anchors to register with the screw receiving openings in the mounting pad. In addition, some elongated devices such as drapery rods, have mounting brackets adjacent opposite ends with two or more fastener receiving openings in the mounting pad of each wall bracket, and it has heretofore been difficult for one person to install such elongated devices with multiple mounting screws and screw anchors at each end of the device.